Humming from the power transformer JC-1

[Kasper]

One of my JC-1 have a humming from the power transformer. When I go from 10watt to 25watt the humming increase a little more. I can hear the humming
1 1/2 meter (60 inchs) from the JC-1.
The other JC-1 is 100% silent. Is this normal with some humming, or shall the transformer be 100% quiet in every JC-1. What is your experience?

Regards

Lars from Norway.

[Peter Nielsen]

Three of my nine JC-1s are emitting an audible hum. One of them is *really* loud. Some days I can hear it even at a 4 meter (12') distance. The other two that are humming are a lot less noisy and require ~1 meter or closer to be heard. Six of them are dead silent though...

My new 2nd Martin Logan Descent sub is emitting a hum that is audible at 4 meters. My older Descent requires ~1 meter or closer to hear the hum...

So, I'd say it's normal. :roll:

The PS Audio HumBuster (http://www.psaudio.com/products/humbusterac.asp) might solve the problem. I haven't tried it yet though, but I belive it will work. Since the amount of humming varies from day to day, it's probably DC components in the AC that is causing the humming.

See the AudioCircle forum (http://www.audiocircle.com/circles/viewtopic.php?t=12706&postdays=0&postorder=asc&start=0) and the diyAudio.com forum (http://www.diyaudio.com/forums/showthread.php?s=&threadid=2080&highlight=) for a wealth of info!

Peter

[psychdoc]

Wow. To me that would be such a disappointment to invest that much money in such a high quality amp in order to get the absolute best sound only to have an audible humming in the background. Yikes. If one was silent I am picky enough to insist that they all would be silent. JMHO.

More and more I read about the bugs from halo line and I end up loving my NewClassic 7100,5250,2250 even more.

[J.H.]

Just what I was thinking psychdoc. How could something that costs this much have hum that is tolerable? Thats doesn't make sense to me. I have an older HCA1205A amp and its 100% silent for a fraction of the cost. This humming issue doesn't make sense. J.H.

[Peter Nielsen]

WOW! You guys are fast to judge and complain!!!! :M

I should be the one to be angry, since I'm the one that spent all the money on humming equipment. Yet I am not angry at all. :T

Note that a Martin Logan sub costs the same as a JC-1. Yet my new Martin Logan hums just as bad as the 9th JC-1. Parasound has one bad hummer in 9. Martin logan has one bad hummer in 2. Marin Logan fails 50%. Parasound fails 10%. That should say something about how good the JC-1s really are...

This is not a Parasound problem. It is a generic problem with equipment using toroidal transfromers.

If your power is good, then all is well. If your power is bad, you need to do something about it.

Balanced power from EquiTech (http://www.equitech.com/) is probably THE best way to solve any power related problems...

FWIW, as a rule of thumb, the larger a toroidal transformer is, the more likely it is that it hums...

Peter

[Peter Nielsen]

I have an older HCA1205A amp and its 100% silent for a fraction of the cost. This humming issue doesn't make sense. J.H.

You might just be lucky enough to have good power in your neighborhood.

If you move to another location, you might find your HCA1205A humming.

Some days, I have no audible humming at all. Some days the humming is really bad. It's all in the power...

There's a good reason people spend thousands of dollars on power filters and regenerators...

Peter

[Peter Nielsen]

If one was silent I am picky enough to insist that they all would be silent.

From what I've heard, Parasound WILL replace the transformer if it hums badly. I've heard about other JC-1 owners that had their transformers replaced.

I might want to get that one transformer replaced, but first I'll want to see what a Humbuster or balanced power can do. I will probably want to go with balanced power in the end anyway, since that's the only "good" power out there.

Peter

[mitch57]

From what I've heard, Parasound WILL replace the transformer if it hums badly. I've heard about other JC-1 owners that had their transformers replaced.

I might want to get that one transformer replaced, but first I'll want to see what a Humbuster or balanced power can do. I will probably want to go with balanced power in the end anyway, since that's the only "good" power out there.

Peter

I don't believe the problem is in the amp. I had the same problem with two different amps. The Rotel RMB-1095 and the Halo A-51. I bought the PS Audio Hum Buster and my Halo A-51 has been completely, absolutely dead silent ever since. I'm convinced it's all about the incoming power to my home.

Just like you said Peter, my amps also would buzz more on some days then others. It doesn't make even the slightest peep now that I have it hooked up to the PS Audio. You should buy one and give it a shot. When I bought mine they agreed to take it back if it didn't solve the problem. And on top of that they agreed to pay the return shipping as well.

If you buy one be sure to let us all know how it turned out for you.

[locomk]

i have a parasound A21, i was getting some hum until i plugged it into my monster mphts3600 power center. now it's all gone. i live about 10 blocks from a pg&e sub station and know the power in my neighborhood is very "polluted". filtering makes a huge difference. I also want to get balanced power one day.

[Peter Nielsen]

I don't believe the problem is in the amp.

Correct. The problem is with the power. When the power is bad, some toroidals will hum more than others....

As you say, the amplifier is probably 100% within specifications.

It's like taking two cars of the same make and model. At a 100MPH impact one breaks in half, killing the driver. The other one doesn't. Does this mean that one of the cars was defective? Probably not... Both cars are within specifications, but external factors were attributing to the end result.

That said, I feel that I might want to get the "1 of 9" amp fixed. It is obviously "very different" from the other ones (different enough to affect resale value!). Going back to the original post; IMHO 1.5 meters is "normal", 4 meters is not. If you want that fixed, then filtering out the DC compontents is the solution.

FYI, I will probably go straight to balanced power. That's the only reason I haven't picked up a Humbuster yet... (Ok, I know I have no excuse for not building one of the circuits yet :B )

Peter

[psychdoc]

Peter,
I was not complaining. I was judging but only in the context of if I was the one who had the humming problem. I was also reflecting on my own thoughts as to my own setup.

This whole hobby is basically "different strokes for different folks" and people will like/dislike many things about every piece of equipment out there and opinions are freely given. No offense was meant, just giving my opinion on what appears to be a bad situation on a very expensive, high profile piece of equipment. Please don't take any comment personally as it was not meant as such.

I still have a difficult time believing it is solely a power situation since you mentioned some of the amps are currently silent. That would mean the rest of the amps should be silent as well. An additional component may fix the symptom but not address the problem. JMHO. Matt

[J.H.]

Peter you have a beautiful system you put together is there a reason you don't have a really,really nice powrer protector/hum breaker? By the way are you still using the C2? You mentioned a while back you wanted to buy a Lexicon processor didn't you? I just switched ordered a B&K Ref50 S2 and sold my Parasound 7100. While the 7100 was very nice I number one can't sit still with what i have but number 2 for aome odd reason the 7100 just was lacking when playing music. The 7100 was just not crisp with 5.1 music and DPLII and I don't know why. The B&K does both very well. Not starting a fight because i still love Parasound but the 7100 was lacking some. J.H.

[Peter Nielsen]

J.H.,

My JC-1s theoretically require 9x1200 Watts of power. In practice, though, two 20 Amp circuits work fine. (Anything less is not enough). The only viable solutuion is something like an EquiTech 5kW unit (http://www.equitech.com/products/industrial/wall.html). I'd like to get one of the wall-mounted ones, but the weight of ~300 lbs scares me off. I have no idea how I would get that sucker physically installed... :B

I'm still using the C2 and waiting for my (first) DEQX (http://www.deqx.com/DEQX-high-definition-audio.html) to arrive. DEQX is having some serious problems with delivery (I ordered my unit on January 8th. I will hopefully receive it in May :E )

Peter

[Peter Nielsen]

FWIW, here's a very economical balanced power alternative (http://www.transcendentsound.com/power_supply.htm) when 1000 watts suffice.

Peter

[Chris D]

Wow, Peter, hope that DEQX works well for you!

[J.H.]

Forgive me what is DEQX? Thanks J.H.

[Peter Nielsen]

Forgive me what is DEQX? Thanks J.H.

A very elaborate digital crossover. My front pair of Maggies (MG20.1) will be actively biamped with four JC-1s. Two Martin Logan Descent active subwoofers will complement the setup, effectively forming what can be called a "tri-amp" setup. See the picture at the bottom of this page (http://www.deqx.com/DEQX-high-definition-audio.html).

To make it short, the DEQX will measure the speakers and room. Then the data is uploaded to PC software that calculates ideal crossover frequencies, etc. The data is finally downloaded back into the DEQX.

Peter

[J.H.]

Wow way over my head. Sounds complicated and EXPENSIVE but very cool. You must have some setup. I don't mind to be nosy but what would you say your whole HT setup audio wise cost you? Also if I'm not mistaken your from Europe right? Thanks for the curious help I have. J.H.

[slayer]

I was working on my system today. I was putting in a 12V trigger off my C2 to power up my Velodyne SMS-1. While back there, I noticed for the first time ever my Earthquake Cinenova Grande amp had a hum going. It would go in and out. We were having a serious rain storm at the time. Not sure if it was the cause but either way it was humming. I have a Monster Cable HTPS-7000 Signature Series Power Conditioner that all my gear is plugged into. I read a steady 123V-124V at all times on my readout.
The only piece of gear that I DO NOT plug into this unit is my amp and my rear sub. I have two dedicated 20a circuits for my system. My amp plugs into one, while my HTPS-7000 plugs into the other. I've talked to Joseph Sahyoun, owner of Earthquake and designer of my amp, several times about my amp. He did not recommend I plug my amp into any type of power conditioner. He called the amp an Arc Welder and that if I could feed it with a 30a circuit, do it. I agree. I leave it powered on at all times. When I first got the amp, I would try to manually turn it on and off. Several times it tripped my 20a breaker so I decided to just leave it on.
Peter, do you know much about that Transcendent Sound unit? I wonder if it would choke my power coming in. I want to make sure my amp gets everything it needs to perform its best.
I still plan on plugging my amp into my HTPS-7000 to see if I hear a difference between the wall power and the conditioned power. I use a Shunyata Research Anaconda VX power cable, http://www.shunyata.com/Content/Products-Helix.Anaconda.html , so I know I don't have a problem between my amp and where I plug it in. I'm curious about the Humbuster and the Transcendent Sound unit. Any thoughts?

[ThomasW]

FWIW, here's a very economical balanced power alternative when 1000 watts suffice.I'm curious about the Humbuster and the Transcendent Sound unit. Any thoughts?
You might find this an interesting read...I consider the Transendent unit to be a ripoff
http://home.comcast.net/~thomasw_2/TranscendentSoundKit.html

For $75 more than the Transendent kit one can buy the 15 amp 70lb Equi=tech "Q" transformer in a box.....

http://home.comcast.net/~thomasw_2/Q-InABox.jpg

[Peter Nielsen]

For $75 more than the Transendent kit one can buy the 15 amp 70lb Equi=tech "Q" transformer in a box.....

Yes, that is (was?) a fantastic value. However, when I checked equitech's page last time, they did not seem to have those discounted units any more...

Peter

[Peter Nielsen]

I don't mind to be nosy but what would you say your whole HT setup audio wise cost you?

Magnepan MG20.1 $12,000/pair
Magnepan MG3.6 $4,350/pair
Magnepan CC3 $995
Magnepan MGMC1 $750/pair
2 Martin Logan Descent $2,895/each
9 Parasound JC-1 $3,500/each
DEQX with Earthworks mic and balanced outputs $4,180
Parasound C2 $3,995
Parasound T3 $600

You do the math :B

Peter

[ThomasW]

However, when I checked equitech's page last time, they did not seem to have those discounted units any more...
According to this link they're going to have more at some point as a part of their permanent inventory.
http://www.equitech.com/products/specials.html

[J.H.]

hold on a minute hold on! You have 9 JC-1s! Are you kidding! 9! You could power the space shuttle with all those amps!Um just for the record that all comes out to $64,160! That must be incredible. I don't think a system could get much better than that. What video system are you using? Projector,LCD,Plasma? I assume Projector. Well my freind that is one hell of a system. Again not to be nosy or maybe I am What in gods name do you do for a living to be able to afford all that equipment? Thanks again J.H.

[nicholtl]

He makes offers to people who can't refuse.

[J.H.]

I see I will not ask another question :E I'm not going to push further :E Forgive me sir :E Have fun with your great equipment no matter how you paid for it :E J.H.

[mitch57]

I wonder if it would choke my power coming in. I want to make sure my amp gets everything it needs to perform its best.
I still plan on plugging my amp into my HTPS-7000 to see if I hear a difference between the wall power and the conditioned power. I use a Shunyata Research Anaconda VX power cable, http://www.shunyata.com/Content/Products-Helix.Anaconda.html , so I know I don't have a problem between my amp and where I plug it in. I'm curious about the Humbuster and the Transcendent Sound unit. Any thoughts?

The Humbuster is a non current limiting device. The term PS Audio uses for it is "Unrestricted high current". Here's a link to their site that describes it. I own one and am thrilled to death with it. I will never look back!

http://www.psaudio.com/cart/ProductDisplay.asp?productID=89

[Chris D]

He makes offers to people who can't refuse.

The "Godfather" Nielsen? I think a new nickname has just been born. :)

[george_k]

Peter, with that kinda money spent I'm surprised you haven't looked into cleaning up your power.

As an alternative to a 300lb wall unit you might want to look into one of the larger units from these guys http://www.toruspower.com/products.htm

[Peter Nielsen]

What in gods name do you do for a living to be able to afford all that equipment? Thanks again J.H.

The answer to your questions is a click away. Click on my name to the right of this post, and select "View Public Profile" from the resulting popup menu...

The trick to afford a high end system when funds are limited, is to buy one component at a time. For instance, I got my JC-1s in 4 batches; 2-2-2-3.

Peter

[Peter Nielsen]

The "Godfather" Nielsen? I think a new nickname has just been born. :)

:T I like that. How do I go about changing my user name to "The Godfather" (assuming it's not already taken) ?

Peter

[Peter Nielsen]

Peter, with that kinda money spent I'm surprised you haven't looked into cleaning up your power.

I guess the reason is that JC-1s don't really need any power cleaning, except when it comes to silencing the physical noise of the transformers.

Equitech also has rack mounted units similar to the Torus Power. However, that's an inferior option. If I go with rack mounted units, I will not be able to balance the power to my projector.

Currently I have wired my media room with two 20A circuits for the audio and one 20A circuit for the projector. Since the projector wiring goes directly from the ceiling down to the house main breaker box, I have no practical way to balance that circuit with a rack mounted unit. I could, however, easily balance the two 20A circuits by using dual Equitech rack mounted units.

Since two rackmounted units are almost as expensive as the wall mounted unit, the ideal solution is to install a wall mounted unit next to the main breaker box and rewire all three media room circuits to use balanced power. I guess I need to hire a bodybuilder or two to help me out with that 300 lbs Equitech unit... :B

I wonder if I really need the "Q"-type wall mounted unit. Since it would be in my garage, I don't care if it hums loudly. I guess a non-Q unit is just as good and saves me a grand or two. What do you think? ThomasW, what do you think?

Peter

[ThomasW]

Whether or not your gear hums you'll get a lowering of the noise floor in both audio and video using BP.

I bought 4 of the "Q" in a box trannys. And everything in the system including 2 Ayre V-5Xe, 6-Aragon 8008BB, etc, is plugged into BP. The effects are cumulative. Statements from power amp mfgr's that their products don't benefit from power conditioning are false.

I started playing with BP years ago buying products from BPT (he uses Plitron trannys). Then built the Transcendent kit and several from scratch DIY projects (all these used Avel Lindberg trannys). Finally I got smart and bought one of the Equi=tech trannys. Equi=tech trannys are in a league of their own, they make the trannys from other companies look like a joke. The day my first "Q" tranny arrived I called Equi=tech and ordered 3 more.... :T

All the Pliton and Avel Lindberg trannys hum, and the heavier the load the louder they hum. Even under heavy loads the Equi=tech trannys are dead quiet.

Here's a photo comparison between a 20 amp Plitron and a 15 amp Equi=tech
http://home.comcast.net/~thomasw_2/CheapskateBP7.html

[Chris D]

:T I like that. How do I go about changing my user name to "The Godfather" (assuming it's not already taken) ?

Peter

Ah, you'd have to send a message to Doug and the other administrators here. For now, though, we'll just bestow the "Godfather" moniker here in Club Parasound. :)

"Godfather, on this great day, the day of your only daughter's wedding, I bring blessings and respect. I pray that her firstborn child would be a male child, with ears of gold and the eyes of an eagle. That he would be named 'High Fidelity Nielsen', with the best of taste in music and movies. Godfather, I ask only one favor...

GIVE ME YOUR DAMN JC-1'S!!!!" ;x(

[Jeff Mayer]

Origianlly Posted by Chris D
Godfather, I ask only one favor...

GIVE ME YOUR DAMN JC-1'S!!!!

Heck, just give me two. :)

[mitch57]

I'll take five please.:amen:

[Peter Nielsen]

According to this link they're going to have more at some point as a part of their permanent inventory.
http://www.equitech.com/products/specials.html


They already do:

http://www.equitech.com/products/industrial/xfmrs/toroid.html
http://www.equitech.com/purchase/prices.html

The 20A model 2QB is $1,159... Almost 3 times as expensive as the former "special" pricing (wasn't that $400 ?).

However, getting three 2QBs is still a lot less expensive than getting one of the wall mounted units :T

Peter

[ThomasW]

The 'specials' when available are trannys made on their automatic winders that end up too tall to fit in their standard rackmount fancy boxes. That's why they're sold at a significant discount.

From that price list posted, the new 'special' trannys haven't been listed yet......

[Peter Nielsen]

From that price list posted, the new 'special' trannys haven't been listed yet......

Oh, I got it! Please post a follow-up here if you happen to see a new special listed...

Seems like it's definitely worth waiting for!

Peter

[Peter Nielsen]

I just noticed the 2005 NEC Article 647.3 (http://www.equitech.com/support/647.html) that says:

Use of a separately derived 120-volt single-phase 3-wire system with 60 volts on each of two ungrounded conductors to a grounded neutral conductor shall be permitted for the purpose of reducing objectionable noise in sensitive electronic equipment locations provided that the following conditions apply.

(1) The system is installed only in commercial or industrial occupancies.
(2) The system's use is restricted to areas under close supervision by qualified personnel.
(3) All of the requirements in 647.4 through 647.8 are met.


Is there a different NEC Article that permits the use of balanced power at a non-commercial facility (e.g. @ Home) ?

Peter

[ThomasW]

Is there a different NEC Article that permits the use of balanced power at a non-commercial facility (e.g. @ Home) ? Not that I'm aware of....

Thousands of people are using BP devices. If there was an inherent problem with them, the mfgr's would have been put out of business long ago by law suits.

If you have questions the Equi=tech people are pretty friendly on the phone.

[Peter Nielsen]

Thousands of people are using BP devices. If there was an inherent problem with them, the mfgr's would have been put out of business long ago by law suits.

Right... I was just worried about the scenario that the house burns down and the insurance company denies my claim because a NEC violation was found...

In Europe (or more precisely, in Finland) this is a major issue, since insurance companies are known to deny claims if code violations are discovered. However, I guess it's not so much of an issue here in the US. From what I've gathered, NEC compliance is important to get the initial house inspection okayed with the Fire Marshal, et. al., but once that is done, nobody really nitpicks on NEC issues...

Oh well, this is already way off-topic...

Peter

[ThomasW]

Here they usually target the cause of the fire.

[Peter Nielsen]

Here they usually target the cause of the fire.

And what happens if against all odds it was a faulty Q transformer that caused the fire and burned down your home? (Nothing is foolproof). Will the insurance company deny your claim, because you had installed a device in your home that is not approved by NEC for use in your home?

Food for thought...

Peter

[Bob Stern]

One of my JC-1's is silent, but the other is audible 20 feet away. Sounds like mine is way beyond normal limits, so I plan to call Parasound.

Peter Nielsen helpfully posted a link to a lengthy technical discussion at DIYaudio (http://www.diyaudio.com/forums/showthread.php?threadid=2080) (thread id 2080).
Reading the DIYaudio thread stimulated some insights of my own that I'd like to share.

The most commonly suggested solution is blocking the DC with a series capacitor.

It seems to me that a cheaper and better solution is the circuit in PS Audio's Humbuster, which appears identical to the circuit shown in the lower left quadrant of mlloyd1's schematic (http://www.diyaudio.com/forums/attachment.php?s=&postid=328821&stamp=1077146064), except that:
(1) PS Audio's capacitors are merely small RF bypass capacitors so that almost all the AC current flows through the diodes rather than the capacitors; and
(2) PS Audio uses two bridge rectifiers in series (one on each leg of the AC power line) to raise the zero-crossing threshold from 1.2 volt to 2.4 volt.

The operating principle of the Humbuster is that 4 back-to-back pairs of high power diodes in series (ie, 2 bridge rectifiers; see photo (http://www.psaudio.com/products/images/306_1.jpg)) prevent current flow within 2.4 volts of the zero-crossing of the AC signal.

The zero crossing is when most of the current spike occurs in response to DC offset in the AC power line. This is a surprising discovery shown in Eva's oscillographs (http://www.diyaudio.com/forums/showthread.php?postid=331815#post331815) in the DIYaudio thread.

High power diodes as in PS Audio's circuit are cheaper and much more compact than huge capacitors, and they should provide less impedance to high current surges during amplifier output peaks.

A balanced transformer such as Equi-Tech is expensive and heavy. It merely shifts the burden of absorbing the DC from the JC-1's transformer to the balanced transformer. There's no theoretical reason the balanced transformer should be less susceptible to hum than the JC-1's transformer. If this works, the only explanation is that the JC-1's transformer is inferior to Equi-Tech's.

I don't see why an ExactPower regulator would help. The schematic in their patent shows an AC-coupled comparator circuit that would not be able to detect or correct DC offset. (I just sent an email asking them to confirm this.)

[Peter Nielsen]

There's no theoretical reason the balanced transformer should be less susceptible to hum than the JC-1's transformer. If this works, the only explanation is that the JC-1's transformer is inferior to Equi-Tech's.

Yes, there is a theoretical reason: The Equi-Tech "Q" transformer (http://www.equitech.com/faq/q.html) is technically different from a regular toroid. (You can easily tell since it is much bigger than a regular toroid with the same rating).

Adding an Equi-Tech transformer also has the great benefit of providing balanced power (http://www.equitech.com/faq/whatis.html) where the voltage to ground is only 60 Volts instead of 120 Volts.

Personally, I would not ship my JC1s anywhere. The risk of components rattling loose in shipping (most notably the power transistors) is too big. You may end up getting back a JC-1 that hums less, but sounds worse. But if you can drop it off at a service center in person it's another story...

Peter

[Bob Stern]

Personally, I would not ship my JC1s anywhere. ... But if you can drop it off at a service center in person it's another storyParasound doesn't allow that. You have to drop it off at a customer service center in San Francisco, then Parasound ships it by courier to their repair facility in another part of San Francisco.

[Bob Stern]

I don't see why an ExactPower regulator would help. The schematic in their patent shows an AC-coupled comparator circuit that would not be able to detect or correct DC offset. I just received an email from Exact Power confirming that their EP15A cannot remove DC offset in the power line.